Silver carp

Silver carp (Hypophthalmichthys molitrix), also called white carp or silver carp. The body is laterally compressed, with a bluish-gray back and white sides and belly. The head is relatively large. The eyes are set very low. The scales are small. A keratinous ridge runs along the midline of the belly from below the pectoral fins straight to the anus. The pectoral fins do not extend beyond the base of the pelvic fins. All fins are grayish-white. Silver carp are impatient by nature and good at jumping. They live in the middle and upper layers of the water.

Silver carp are typical filter-feeding fish. At the fry stage they mainly eat zooplankton, and once they grow longer than 1.5 cm they gradually switch to eating phytoplankton. They also eat soybean milk, soybean residue powder, wheat bran and rice bran, and they prefer artificial micro-pellet compound feed. They are suitable for farming in fertile water. The length of the intestine is about 6-10 times the body length.

Silver carp reach sexual maturity 1-2 years earlier than grass carp. Mature individuals are also smaller; generally females of 3 kg or more can reach maturity. A female of about 5 kg has a relative fecundity of about 40,000-50,000 eggs per kg of body weight, and an absolute fecundity of 200,000-250,000 eggs. The eggs are pelagic. The spawning period is the same as that of grass carp. In recent years it has been found that silver carp farmed in the mainland show signs of degeneration, mainly smaller individuals and earlier maturation, so attention should be paid to introducing fry from the place of origin for purification and rejuvenation.

Silver carp are also a large fish, reaching 30-40 kg in natural rivers. Under pond farming conditions, if feed is sufficient, 1-year-old fish can reach around 0.8 kg. For edible commercial silver carp suitable for market, a body weight of 1.5-2 kg is better.